1 files changed, 0 insertions, 319 deletions
diff --git a/ICSharpCode.Decompiler/ILAst/GotoRemoval.cs b/ICSharpCode.Decompiler/ILAst/GotoRemoval.cs
deleted file mode 100644
index fafe13e1..00000000
--- a/ICSharpCode.Decompiler/ILAst/GotoRemoval.cs
+++ /dev/null
@@ -1,319 +0,0 @@
-// Copyright (c) 2011 AlphaSierraPapa for the SharpDevelop Team
-// 
-// Permission is hereby granted, free of charge, to any person obtaining a copy of this
-// software and associated documentation files (the "Software"), to deal in the Software
-// without restriction, including without limitation the rights to use, copy, modify, merge,
-// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
-// to whom the Software is furnished to do so, subject to the following conditions:
-// 
-// The above copyright notice and this permission notice shall be included in all copies or
-// substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
-// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
-// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
-// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-
-using System;
-using System.Diagnostics;
-using System.IO;
-using System.Collections.Generic;
-using System.Linq;
-
-namespace ICSharpCode.Decompiler.ILAst
-{
-	public class GotoRemoval
-	{
-		Dictionary<ILNode, ILNode> parent = new Dictionary<ILNode, ILNode>();
-		Dictionary<ILNode, ILNode> nextSibling = new Dictionary<ILNode, ILNode>();
-		
-		public void RemoveGotos(ILBlock method)
-		{
-			// Build the navigation data
-			parent[method] = null;
-			foreach (ILNode node in method.GetSelfAndChildrenRecursive<ILNode>()) {
-				ILNode previousChild = null;
-				foreach (ILNode child in node.GetChildren()) {
-					if (parent.ContainsKey(child))
-						throw new Exception("The following expression is linked from several locations: " + child.ToString());
-					parent[child] = node;
-					if (previousChild != null)
-						nextSibling[previousChild] = child;
-					previousChild = child;
-				}
-				if (previousChild != null)
-					nextSibling[previousChild] = null;
-			}
-			
-			// Simplify gotos
-			bool modified;
-			do {
-				modified = false;
-				foreach (ILExpression gotoExpr in method.GetSelfAndChildrenRecursive<ILExpression>(e => e.Code == ILCode.Br || e.Code == ILCode.Leave)) {
-					modified |= TrySimplifyGoto(gotoExpr);
-				}
-			} while(modified);
-			
-			RemoveRedundantCode(method);
-		}
-		
-		public static void RemoveRedundantCode(ILBlock method)
-		{
-			// Remove dead lables and nops
-			HashSet<ILLabel> liveLabels = new HashSet<ILLabel>(method.GetSelfAndChildrenRecursive<ILExpression>(e => e.IsBranch()).SelectMany(e => e.GetBranchTargets()));
-			foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
-				block.Body = block.Body.Where(n => !n.Match(ILCode.Nop) && !(n is ILLabel && !liveLabels.Contains((ILLabel)n))).ToList();
-			}
-			
-			// Remove redundant continue
-			foreach(ILWhileLoop loop in method.GetSelfAndChildrenRecursive<ILWhileLoop>()) {
-				var body = loop.BodyBlock.Body;
-				if (body.Count > 0 && body.Last().Match(ILCode.LoopContinue)) {
-					body.RemoveAt(body.Count - 1);
-				}
-			}
-			
-			// Remove redundant break at the end of case
-			// Remove redundant case blocks altogether
-			foreach(ILSwitch ilSwitch in method.GetSelfAndChildrenRecursive<ILSwitch>()) {
-				foreach(ILBlock ilCase in ilSwitch.CaseBlocks) {
-					Debug.Assert(ilCase.EntryGoto == null);
-					
-					int count = ilCase.Body.Count;
-					if (count >= 2) {
-						if (ilCase.Body[count - 2].IsUnconditionalControlFlow() &&
-						    ilCase.Body[count - 1].Match(ILCode.LoopOrSwitchBreak)) 
-						{
-							ilCase.Body.RemoveAt(count - 1);
-						}
-					}
-				}
-				
-				var defaultCase = ilSwitch.CaseBlocks.SingleOrDefault(cb => cb.Values == null);
-				// If there is no default block, remove empty case blocks
-				if (defaultCase == null || (defaultCase.Body.Count == 1 && defaultCase.Body.Single().Match(ILCode.LoopOrSwitchBreak))) {
-					ilSwitch.CaseBlocks.RemoveAll(b => b.Body.Count == 1 && b.Body.Single().Match(ILCode.LoopOrSwitchBreak));
-				}
-			}
-			
-			// Remove redundant return at the end of method
-			if (method.Body.Count > 0 && method.Body.Last().Match(ILCode.Ret) && ((ILExpression)method.Body.Last()).Arguments.Count == 0) {
-				method.Body.RemoveAt(method.Body.Count - 1);
-			}
-			
-			// Remove unreachable return statements
-			bool modified = false;
-			foreach(ILBlock block in method.GetSelfAndChildrenRecursive<ILBlock>()) {
-				for (int i = 0; i < block.Body.Count - 1;) {
-					if (block.Body[i].IsUnconditionalControlFlow() && block.Body[i+1].Match(ILCode.Ret)) {
-						modified = true;
-						block.Body.RemoveAt(i+1);
-					} else {
-						i++;
-					}
-				}
-			}
-			if (modified) {
-				// More removals might be possible
-				new GotoRemoval().RemoveGotos(method);
-			}
-		}
-		
-		IEnumerable<ILNode> GetParents(ILNode node)
-		{
-			ILNode current = node;
-			while(true) {
-				current = parent[current];
-				if (current == null)
-					yield break;
-				yield return current;
-			}
-		}
-		
-		bool TrySimplifyGoto(ILExpression gotoExpr)
-		{
-			Debug.Assert(gotoExpr.Code == ILCode.Br || gotoExpr.Code == ILCode.Leave);
-			Debug.Assert(gotoExpr.Prefixes == null);
-			Debug.Assert(gotoExpr.Operand != null);
-			
-			ILNode target = Enter(gotoExpr, new HashSet<ILNode>());
-			if (target == null)
-				return false;
-			
-			// The gotoExper is marked as visited because we do not want to
-			// walk over node which we plan to modify
-			
-			// The simulated path always has to start in the same try-block
-			// in other for the same finally blocks to be executed.
-			
-			if (target == Exit(gotoExpr, new HashSet<ILNode>() { gotoExpr })) {
-				gotoExpr.Code = ILCode.Nop;
-				gotoExpr.Operand = null;
-				if (target is ILExpression)
-					((ILExpression)target).ILRanges.AddRange(gotoExpr.ILRanges);
-				gotoExpr.ILRanges.Clear();
-				return true;
-			}
-			
-			ILNode breakBlock = GetParents(gotoExpr).FirstOrDefault(n => n is ILWhileLoop || n is ILSwitch);
-			if (breakBlock != null && target == Exit(breakBlock, new HashSet<ILNode>() { gotoExpr })) {
-				gotoExpr.Code = ILCode.LoopOrSwitchBreak;
-				gotoExpr.Operand = null;
-				return true;
-			}
-			
-			ILNode continueBlock = GetParents(gotoExpr).FirstOrDefault(n => n is ILWhileLoop);
-			if (continueBlock != null && target == Enter(continueBlock, new HashSet<ILNode>() { gotoExpr })) {
-				gotoExpr.Code = ILCode.LoopContinue;
-				gotoExpr.Operand = null;
-				return true;
-			}
-			
-			return false;
-		}
-		
-		/// <summary>
-		/// Get the first expression to be excecuted if the instruction pointer is at the start of the given node.
-		/// Try blocks may not be entered in any way.  If possible, the try block is returned as the node to be executed.
-		/// </summary>
-		ILNode Enter(ILNode node, HashSet<ILNode> visitedNodes)
-		{
-			if (node == null)
-				throw new ArgumentNullException();
-			
-			if (!visitedNodes.Add(node))
-				return null;  // Infinite loop
-			
-			ILLabel label = node as ILLabel;
-			if (label != null) {
-				return Exit(label, visitedNodes);
-			}
-			
-			ILExpression expr = node as ILExpression;
-			if (expr != null) {
-				if (expr.Code == ILCode.Br || expr.Code == ILCode.Leave) {
-					ILLabel target = (ILLabel)expr.Operand;
-					// Early exit - same try-block
-					if (GetParents(expr).OfType<ILTryCatchBlock>().FirstOrDefault() == GetParents(target).OfType<ILTryCatchBlock>().FirstOrDefault())
-						return Enter(target, visitedNodes);
-					// Make sure we are not entering any try-block
-					var srcTryBlocks = GetParents(expr).OfType<ILTryCatchBlock>().Reverse().ToList();
-					var dstTryBlocks = GetParents(target).OfType<ILTryCatchBlock>().Reverse().ToList();
-					// Skip blocks that we are already in
-					int i = 0;
-					while(i < srcTryBlocks.Count && i < dstTryBlocks.Count && srcTryBlocks[i] == dstTryBlocks[i]) i++;
-					if (i == dstTryBlocks.Count) {
-						return Enter(target, visitedNodes);
-					} else {
-						ILTryCatchBlock dstTryBlock = dstTryBlocks[i];
-						// Check that the goto points to the start
-						ILTryCatchBlock current = dstTryBlock;
-						while(current != null) {
-							foreach(ILNode n in current.TryBlock.Body) {
-								if (n is ILLabel) {
-									if (n == target)
-										return dstTryBlock;
-								} else if (!n.Match(ILCode.Nop)) {
-									current = n as ILTryCatchBlock;
-									break;
-								}
-							}
-						}
-						return null;
-					}
-				} else if (expr.Code == ILCode.Nop) {
-					return Exit(expr, visitedNodes);
-				} else if (expr.Code == ILCode.LoopOrSwitchBreak) {
-					ILNode breakBlock = GetParents(expr).First(n => n is ILWhileLoop || n is ILSwitch);
-					return Exit(breakBlock, new HashSet<ILNode>() { expr });
-				} else if (expr.Code == ILCode.LoopContinue) {
-					ILNode continueBlock = GetParents(expr).First(n => n is ILWhileLoop);
-					return Enter(continueBlock, new HashSet<ILNode>() { expr });
-				} else {
-					return expr;
-				}
-			}
-			
-			ILBlock block = node as ILBlock;
-			if (block != null) {
-				if (block.EntryGoto != null) {
-					return Enter(block.EntryGoto, visitedNodes);
-				} else if (block.Body.Count > 0) {
-					return Enter(block.Body[0], visitedNodes);
-				} else {
-					return Exit(block, visitedNodes);
-				}
-			}
-			
-			ILCondition cond = node as ILCondition;
-			if (cond != null) {
-				return cond.Condition;
-			}
-			
-			ILWhileLoop loop = node as ILWhileLoop;
-			if (loop != null) {
-				if (loop.Condition != null) {
-					return loop.Condition;
-				} else {
-					return Enter(loop.BodyBlock, visitedNodes);
-				}
-			}
-			
-			ILTryCatchBlock tryCatch = node as ILTryCatchBlock;
-			if (tryCatch != null) {
-				return tryCatch;
-			}
-			
-			ILSwitch ilSwitch = node as ILSwitch;
-			if (ilSwitch != null) {
-				return ilSwitch.Condition;
-			}
-			
-			throw new NotSupportedException(node.GetType().ToString());
-		}
-		
-		/// <summary>
-		/// Get the first expression to be excecuted if the instruction pointer is at the end of the given node
-		/// </summary>
-		ILNode Exit(ILNode node, HashSet<ILNode> visitedNodes)
-		{
-			if (node == null)
-				throw new ArgumentNullException();
-			
-			ILNode nodeParent = parent[node];
-			if (nodeParent == null)
-				return null;  // Exited main body
-			
-			if (nodeParent is ILBlock) {
-				ILNode nextNode = nextSibling[node];
-				if (nextNode != null) {
-					return Enter(nextNode, visitedNodes);
-				} else {
-					return Exit(nodeParent, visitedNodes);
-				}
-			}
-			
-			if (nodeParent is ILCondition) {
-				return Exit(nodeParent, visitedNodes);
-			}
-			
-			if (nodeParent is ILTryCatchBlock) {
-				// Finally blocks are completely ignored.
-				// We rely on the fact that try blocks can not be entered.
-				return Exit(nodeParent, visitedNodes);
-			}
-			
-			if (nodeParent is ILSwitch) {
-				return null;  // Implicit exit from switch is not allowed
-			}
-			
-			if (nodeParent is ILWhileLoop) {
-				return Enter(nodeParent, visitedNodes);
-			}
-			
-			throw new NotSupportedException(nodeParent.GetType().ToString());
-		}
-	}
-}